Trouble Diagnosis For Abnormal Pressure

Both High- And Low-pressure Sides Are Too High:

High-pressure Side Is Too High And Low-pressure Side Is Too Low:

High-pressure Side Is Too Low And Low-pressure Side Is Too High:

Both High- And Low-pressure Sides Are Too Low:

Low-pressure Side Sometimes Becomes Negative:

Low-pressure Side Becomes Negative:

Whenever system's high and/or low side pressure is abnormal, diagnose using a manifold gauge. The marker above the gauge scale in the following tables indicates the standard (normal) pressure range. Since the standard (normal) pressure, however, differs from vehicle to vehicle, refer to ("Ambient air temperature-to-operating pressure table").